In recent years, electronic equipment such as AV devices, personal computers and portable communication devices is rapidly made portable and cordless. For a driving power source of these electronic devices, nickel cadmium storage batteries, nickel metal-hydride storage batteries, lithium secondary batteries and the like have been typically used since they have high reliability and easy maintainability. These batteries are also used in various other applications, particularly increasingly used as driving power sources in power-assisted bicycles, lawn mowers, electric vehicles and other applications where large load characteristics are required. Thus, there is a much need for batteries that have larger current charge/discharge performance suitable for use as driving power sources in these applications.
The battery for use as driving power sources is typically assembled as a battery pack or a battery module in which multiple batteries are connected mutually between different polarities. Traditionally, an inter-battery connection plate 34 as shown in FIG. 12 has been used to connect batteries. The inter-battery connection plate 34 consists of a metal plate obtained by cutting a hoop-like metal into predetermined lengths. Specifically, the connection areas at the both ends of the inter-battery connection plate 34 are connected via the welds 35 to the case bottom 32 of the battery 31a and to the sealing plate 33 of the battery 31b respectively.
A battery connection member is also known that consists of a single plate having a first connection area that comes into contact with the bottom of one cell and a second connection area that is formed as an annular recess or a step that comes into contact with the sealing plate of the other cell (Refer, for example, Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open No. 2002-246003